Signal-transmitter.



W. J. DAVIS'& D. G. KNITTEL.

SIGNAL TRANSMITTER.

APPLICATION FILED JAN. 2. 1915.

Patented Mar. 14, 1916.

m .T G i3 illE 2 gum WITNESSES THE COLUMBIA PLANOGRAPH .60., WASHINGTON,D. c.

invrrnn srarns rarniar canto WILLIAM J. DAVIS, OF PITTSBURGH, AND DAVIDG. KNITTEL, OF WILDVJOOD, PENN- SYLVANIA, ASSIGNORS TO AMERICAN FIREALARM COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

SIGNAL-TRANSMITTER.

Specification of Letters Patent.

Application filed January 2, 1915. Serial No. 152.

To all whom it may'concern Be it known that we, WILLIAM J. DAVIS,residing at Pittsburgh, and DAVID G. KNIT- TEL, residing at WVildwood,both in the county of Allegheny and State of Pennsylvania, citizens ofthe United States, have invented or discovered certain new and usefulImprovements in Signal-Transmitters, of which improvements the followingis a specification.

Our invention relates to electric signal transmitting instruments suchas are used in police and fire alarm boxes to send de-' siredsignals toa central station, and which are of the general character of those shownin our United States Patent No. 1,092,919, and in Patent No. 1,092,918granted to David G. Knittel. The mechanisms usually employed for thispurpose comprise, as shown in-th'ese patents, special-signal andbox-number wheels, mounted onseparate rotatable shafts, and providedwith peripheral projections adapted to move a circuit controlling arm tointerrupt an electric circuit at predetermined intervals. The electricalcircuits are provided with one or more shunts, and a suitable clock-workmechanism, indicator and pulling handle are provided to control andoperate the transmitter.

It has been found that, in transmitters of this general type, theindicator and pulling handle may be so manipulated as to transmitincorrect or confused signals; and dishonest employees avail themselvesof this circumstance when, at an appointed hour for mak-- ing a reportto a central station, they have not gone to the box from which suchreport I should be made, and therefore desire that the signal shall notindicate the number of the box at which the report is actually made.

It is the primary object of our present in vention to provide a signaltransmitting instrument which, although adequate in every respect forits intended purpose, may not be so manipulated that it will ransmit anincorrect or confused boX-num er signal.

A further object is to simplify the general construction, and to improvethe operation of such signal transmitters.

In the accompanying sheet of drawings, forming part of thespecification, the preferred embodiment of the invention is illustratedas applied to police boxes.

Figure l is a face View of the support or door to which such mechanismsare usually attached, the figure showing the operating handle and theindicator in full lines, and some of the mechanism in dotted lines; Fig.2 is a view partly in section and partly in side elevation of theconstruction shown in Fig. 1; Figs. 3 and 4 are sectional views taken,respectively, on the lines III-III and IVIV, Fig. 2; Fig. 5 is asectional view to enlarged scale,.taken on the line V-V, Fig. 4; andFig. 6 a sectional View in the plane of the winding shaft, showing adetail of construction.

In the several figures like numerals are used to designate like parts.

Referring to the drawings, the entire mechanism is shown as mounted on asuitable support 1, which may be an interior door of a police reportingbox, the indicator 2 and pulling handle 3 being on the outer, and theremainder of the mechanism on the inner, face of the door. Theclock-work mechanism, indicated particularly in Fig. 2, may be of anysuitable type, and is preferably so constructed that a turning of thehandle 3 through a predetermined arc will cause the clock-work spring 4to turn a shaft 5 through one complete revolution. This shaft is in thisinstance provided with a boxnumber wheel 6 and a single special-signalwheel 7, which are suitably provided with means preferably in the formof peripheral projections, to move an arm 8, pivoted, as at 9', to anangular mounting piece 10, which is adjustab'ly secured to a plate 11.However, it will be understood that the shaft 5 may be provided withsuitable means other than the irregular signal wheels for moving the arm8 as desired- To afford the desired adjustment of the arm 8, themounting piece is provided with Patented Mar. 14, 1916.

19, held yieldingly in circuit-closing posi- To raise the arm 8 forinterrupting the circuit, the signals wheels are provided withprojections, which may be arranged to of feet the transmission of anydesired signal or signals. In so far as, in the present embodiment ofour invention, the box-number '7 signal is transmitted each time. thebox is pulled and the transmission of special or 'code signals is'at theoption of the person sending. the signal, the operation of thetransmitter 15 the same as that'o'f the transmitters shown the abovementioned patents. However, in the present transmitter, the constructionis such that the special-signal wheel is adapted to send but one signal,andthat a relatively prolonged call alarm,

intended to indicate that the person at the signal transmitting boxdesires to be placed in telephone communication with the centralstation. To such end the special signal wheel 7 is provided with arelatively pro longed projection 20, Which, through suitable means to beexplained presently, is adapted to raise the arm 8.

The adjustment of the transmitter to send the special signal. ortelephone call may be effected by means of the indicator 2 secured toone end of a rotatably mountedshaft 21, which has a lever 22 attached toits opposite end, and which maybe held yieldingly in one of its twoalternate positions by means of a spring 27. At the end of this leverthere is slidably mounted a dog 23, provided with a pin 24;, whichextends through a longitudinally disposed slot 25 of such lever, andinto an arc-shaped slot 26 of the arm 8. The arc 26 is struck with aradius having its center the axis of the shaft 21, the arrangement beingsuch that no movement of the indicator 2 will be effective to move thecircuit-controlling arm 8. By moving the indicator to the telephoneposition shown in dotted lines in Figs. 1, 3 and a, the lever 22 willbebrought to a position wherein the dog 23 will be in the path of theprojection 20,so that,when the handle 3 is pulled to set the mechanismin operation,

. such projection will, as the shaft 5 turns in is effected by theprojecting teeth of the boxnumber wheel 6, which teeth engage a roller28 suitably mounted on the lower side of the arm.

It is desirable in police boxes that the signaling instrument be setnormally to transmit only the box number, such signal indicatingthat'the patrol wagon is wanted. Therefore, to the end that, after theinstrument hasbeen set to transmit a special signal in addition to theboxnumber, the mechanism will be automatically reset for the box numberabove, the special-signal wheel is provided with an abutment 29 adaptedto engage the side of the dog 23 and thus move the lever 22 to theposition indicated in dotted lines'in Fig. 4. When the lever 22 is inthis position it will be understood that the indicator 'arm 2 will be inthe full line position of Fig. 1. j r 7 It has already been explainedthat nomanipulation of the arm 2 can in any way'interfere with thetransmission of the correct box-number signal when the instrument is inoperation. It is equally true that the circuit may not be interrupted bymanipulating the arm.2 when instrument is idle. It remains now toexplain the construction of the pulling mechanism to the same ends.

F or this purpose, in the present embodiment of our invention weinterpose a clutch between the pulling handle and the winding orstarting shaft, and a second clutch be tween such shaft and theclockworkniecha nlsm means are provided to release thefirst named clutchupon a predetermined rotation of the pulling handle and immediatelyafter the second named clutch has become operative; and furthermoremeans are pro vided to hold the first named clutch in released positionuntil the transmitting mechanism has passed through a complete cycle 7of operation. I

Referring now to the drawings, and par-f ticularly to Figs. 2 and 3, thearm 3 is secured to a rotatably mounted shaft 30, provided at its innerend with a plate 31, which is integrally formedwith such shaft, and heldyieldingly in the position shown in Fig. 3 by means of a spring'32.Pivotally secured to such plate, and heldyieldingly toward the center ofthe shaft 30, there is a pawl having a. finger 33 adapted to fit into a'recess 34: of a collar 35 secured to the wind ing shaft 36. Such pawlhas, also, a second finger 37, which, when the handle 3 has been pulledthrough a predetermined arc,

opening 41, through which the pawl-finger 33 may extend, and with adetent 42 adapted to engage a stop 50 and to hold the locking ring inits indicated position against the tension of a spring 43 secured tosuch ring. The stop 50 is provided with a platelike portion 51, wherebyit is secured to the door 1, and which portion acts as a stop to holdthe plate 31 in its indicated position.

lVhen the instrument is in its normal position, ready for operation, theseveral parts of the clutch and lock are in the positions indicated infull lines in Fig. 3. The turning of the pulling arm 3 is eifective,through plate 31, pawl-finger 33 and collar 35, to correspondinglyrotate the Winding shaft 36, hen such shaft has been turned sullicientlyto cause the motor spring 4 to engage the clockwork mechanism in amanner to be presently explained, the pawl-finger 33 is thrown outwardlyby the engagement of the finger 37 with the roller 38. This releases thearm 3 from the shaft 36, and also releases the locking collar 39, whichcollar, under the tension of the spring 43, immediately flies back toits normal position, and in such position eilectively prevents the pawlfinger 33 from engaging collar 35, and hence the shaft 36, until theinstrument has passed through its cycle of operation.

The clutch between the winding shaft 36 and the clockwork mechanism isillustrated particularly in Figs. 1 and 6, the latter being a sectionalview on aplane passing through the axis of the winding shaft. As shown,such clutch may be a pawl and ratchet construction. Secured to the shaft36 there is a sleeve 44, to which the inner end of the spring 4 isattached, and which isprovided at one end with a ratchet wheel 45.Surrounding such wheel, and rotatably mounted on the shaft 36, there isa cupshaped spur gear 46, provided with a pawl 47, held yieldinglytoward the ratchet wheel by means of a spring 48. The teeth of theratchet 45 are so spaced with relation to the angular distance betweenthe end of the pawl-finger 37 and the roller 38 that the pawl 47 willengage the next successive tooth of the ratchet 45 immediately beforethe pawlfinger is, by the striking of the finger 37 against the roller38, thrown out of engagement with the collar 35.

In describing the operation of the signal transmitting instrument, itwill be assumed first that the indicator has been set for the telephoneposition, that is, the position in which special-signal mechanism willbe brought into action. The instrument is set in motion by pulling orturning the handle 3 in a clock-wise direction, which, through plate 31,pawl-finger 33 and collar 35, causes the winding shaft 36 tocorrespondingly turn until the finger 37 strikes, and is thrownoutwardly by, the roller 38. This releases the finger 33 from the collar35 as well as from the locking ring 39, and thus places the movement ofthe winding shaft entirely beyond the control of the one sending thesignal, it being understood that as soon as the locking rin 39 isreleased it flies back under the tension of spring 43, to the startingposition. Immediately before the pawl 33, 37 has been thrown outwardlythe ratchet wheel 45 has been turned sufliciently to permit the pawl 47of spur gear 46 to engage the next successive ratchet, and thus couplethe clock-work mechanism with the spring 4. Such mechanism then drivesthe shaft 5 through a. complete revolution, during which the arm 8 isfirst raised by the projection 20 of the special signal wheel to openthe electric circuit for sounding the telephone call, such projectionacting through dog 23 and pin 24; and the arm is then raised, by meansof the teeth on the box-number wheel, a plurality of times to indicatethe number of the box from which the signal is sent. The furtherrotation of the shaft 5 causes the abutment 29 of the special-signalwheel to engage the side of the dog 23 and swing the indicator toalternate or wagon-calling position.

The operation of the instrument when set to transmit only the box numberis the same as that just described with the exception that thespecial-signal wheel is not called into action.

We claim as our invention:

1. In a signal transmitter, the combination of a movable circuitmake-and-break member, a rotatable signal wheel, a manually operableindicator provided with an arm, and a dog engaging said member andslidably mounted in said arm, the movement of the indicator beingeffective to bring the dog into a position to cause the circuitmakeand-break member to be moved by the signal wheel but said memberbeing immovable by the movement of the indicator.

2. Ina signal transmitter, the combina tion of a pivotally mountedmake-and-break member provided with an arcuate slot, a rotatable signalwheel, a manually rotatable indicator having an arm i'nredly secured toit, and a dog slidably mounted in such arm and provided with a pinengaging the makea-nd-break member through said slot there of, therotation of said indicator being effective to bring said dog into aposition to cause said member to be moved by the signal wheel.

3. In a signal transmitter, the combination of an arm movable to makeand break an electric circuit, a rotatable shaft provided with two setsof detents one for moving said arm to transmit a box-number signal andthe other to transmit a special signal, the detents for transmitting theboxnumber signal being effective to move the arm upon each rotation ofthe shaft, a dog manually movable to a position for causing saidspecial-signal detents to transmit a signal in sequence with thebox-number signal, and means effective upon the rotation of said shaftto remove said dog from its signal-transmitting position.

4. In a signal transmitter, the combination of a circuit make-and-breakmember, means including a clock-work mechanism for moving said member, arotatable shaft for setting such mechanism in operation, a

' shaft.

5. In a signal transmitter, the combina- Copies of this patent may beobtained for tion of a circuit make-and-break member, means Including aclock-work mechanism for moving said member, a rotatable shaft forsetting such mechanism in operation, a rotatable operating memberincluding 'a pawl held yieldingly in engagement with the shaft, meanseffective upon'the rotation of the shaft to release the pawl, a lockingmember through an aperture of which said pawl engages the shaft, andmeans for caus 'ing said locking memberto hold said pawl from engagementwith the shaft when the.

pawl has been released therefrom and until after a further movement ofthe shaft.

In testimony whereof we have hereunto set our hands.

WILLIAM J, DAVIS. DAVID e. KNITTEL.

Witnesses PAUL N. CRIToHLow, FRANCIS J. TOMASSON.

five cents each, by addressing the Commissioner of Patents,

Washington. D. C.

